Abstract:

Due to unreasonable agricultural practices, soil degradation in banana cropping system is becoming more and more serious, which restricts the healthy and sustainable development of banana industry in China. Plant coverage could improve soil physical and chemical properties and optimize soil microbial community structure, which is an important farming practice to improve soil degradation in agricultural ecosystems. In this study, through the wide-narrow row planting method, the traditional planting method with bare soil was used as control, cultivated saritro [Macroptilium atropurpureum (DC.) Urb.] and natural weeds in wide rows were used as plant coverage treatments. With continuous positioning experiments, based on the high-throughput sequencing of the collected soil samples, the differences in soil fungal diversity and community structure were analyzed with plant coverage treatments under banana cropping system, which would explore the sustainable utilization of soil in banana production. The results showed that there were significant differences in the composition of fungal communities under different plant coverage treatments in banana cropping system, and showed an increasing trend with the continuous of plant coverage. According to the function prediction of FUNguild, compared with the bare soil control, the Saprotroph Symbiotroph guilds in 2019 and 2020 increased significantly (P≤0.05), and the fungal community of Pathogen Saprotroph guilds in 2020 decreased significantly (P≤0.05). The results of co-occurrence network analysis showed that compared with the bare soil control, the community complexity was no difference in the plant coverage treatments, but the community stability was higher. However, the differences in the core microorganisms reflected that saritro treatment reduced the dominance of Fusarium ASV, which would reduce the risk of occurrence of soil-borne disease Fusarium wilt in banana. Saritro treatment effectively increased the symbiotic beneficial fungal guilds, reduced the potential pathogenic fungal guilds, which was beneficial to maintain soil health in banana cropping system. The planting mode combining wide and narrow rows with inter-row cover plants could effectively improve soil microbial diversity, which is conducive to sustainable development of banana industry.

Key words: cover plant, banana, soil fungi, diversity, community structure